JP4996854B2 - Aluminum alloy material for high temperature and high speed forming, method for manufacturing the same, and method for manufacturing aluminum alloy formed product - Google Patents

Description

  The present invention is a high-temperature high-speed high-speed forming aluminum alloy material suitable for manufacturing an aluminum alloy member having a complicated shape difficult to be formed by a cold press and requiring high strength by high-temperature high-speed forming. It is about.

Al-Mg aluminum alloys are known to exhibit a superplastic phenomenon exhibiting a high elongation of over 300% at a strain rate of about 10 ^-3 / s at high temperatures. An aluminum alloy plate for superplastic forming that can be formed into a complex shape that is difficult to manufacture by press forming at room temperature by heating the aluminum alloy plate to a high temperature and forming it into an arbitrary shape by gas pressure or the like A technique related to this is disclosed in, for example, Document 1.
Recently, a technology related to high-temperature high-speed molding that significantly increases productivity by increasing the strain rate during high-temperature molding by an order of magnitude or more, for example, a strain rate of 10 ⁻² to 1 / s, is disclosed in the following patent document, for example. 2-7.
Japanese Patent No. 2831157 JP-A-8-199272 Japanese Patent No. 3145904 Japanese Patent Laid-Open No. 10-259441 JP 2003-342665 A JP 2004-225114 A JP 2004-285390 A

In superplastic forming, in which Al-Mg aluminum alloy is formed at a strain rate of 10 ^-3 / s or less, sliding at the grain boundary is the main deformation mechanism, so the crystal grains of the material before forming are fine. It is known that the superplastic forming elongation is higher. For example, in Patent Document 1 relating to superplastic forming, the average crystal grain size is defined as 20 μm or less in order to ensure high superplastic formability.

On the other hand, in high-temperature high-speed forming performed in a high strain rate region of 10 ⁻² to 1 / s, sub-crystal grains are formed in the crystal grains constituting the aluminum alloy during forming. The term “sub-crystal grain” as used herein refers to a grain composed of a grain boundary (called a sub-crystal grain boundary) whose grain boundary angle, which is an orientation difference between adjacent grains, is less than 15 degrees. It is considered that the subgrain structure formed during the molding has a strong influence on the high-temperature high-speed moldability and the strength of the molded product after molding. However, in the past Al-Mg-based aluminum alloys, what is the optimal subcrystalline structure morphology for high-temperature high-speed formability has not been studied. For example, in Patent Document 2, the average crystal grain size of the material before molding is defined as 15 to 120 μm, and an appropriate amount of Mn, Cr, Zr, etc. is added for the purpose of preventing abnormal growth of crystal grains during high temperature and high speed molding. However, all are related to the grain structure, and the subcrystalline structure has not been studied. Similarly in Patent Document 4, the average crystal grain size is defined as 20 to 200 μm, and an appropriate amount of Mn, Cr, Zr, etc. is added to make the crystal grains finer during recrystallization of the alloy during high temperature deformation. However, these are also matters concerning crystal grains.

  The present invention has been made against the background of the above circumstances, and the subcrystalline structure formed inside the crystal grains during high temperature deformation of the Al-Mg based aluminum alloy, the high temperature high speed formability and the strength of the molded product after the completion of molding. To provide an aluminum alloy material having a specific optimum alloy composition capable of forming a subcrystalline structure capable of achieving both high-temperature high-speed formability and high strength after forming, and a method for producing the same. With the goal.

  First, as a result of intensive studies on the influence of the subgrain structure on the high-temperature and high-speed formability, if the subgrain structure has a finely developed structure, recrystallization occurs sequentially during high-temperature and high-speed forming. It became clear that the high temperature high speed molding elongation was shown compared with the case where it became the structure where the grain disappeared. Furthermore, the strength of the molded product after high-temperature high-speed molding is higher than that in the case where the microstructure in which the subgrain structure is finely developed is recrystallized during high-temperature high-speed molding or after molding to have a subgrain-free structure. It became clear that it was expensive. In addition, in order for the subgrain structure developed during high-temperature and high-speed deformation to exist stably without recrystallization at high temperatures, finely dispersed particles of transition elements such as Mn and Zr exist uniformly and densely in the matrix. It became clear that there was a need.

Based on these findings, the present inventors have intensively studied the amount and combination of various transition elements necessary for stabilizing the subgrain structure, and by adding appropriate amounts of Mn and Zr, The present inventors have found that these transition element-based dispersed particles are uniformly and densely distributed in the matrix, and have made the present invention. That is, the present invention
(1) Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, the balance being Al and a Atsushi Ko high-speed molding aluminum alloy material ing from unavoidable impurities,
An aluminum alloy material for high-temperature high-speed forming, characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm exist as Mn and Zr-based precipitates at a distribution density of 300,000 particles / mm ² or more ,
(2) Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, and Cr: 0.05 to 0.5 mass%, V: 0.01 to 0.1 mass%, Sc: 0.01 to 0.4 mass%, Ti: 0.001 to 0.1 mass%, B: 0.0001 to 0.05 mass%, Be: 0.0001 to 0.01 mass% comprise two or more, the balance being a high-temperature high-speed molding aluminum alloy material ing of Al and unavoidable impurities,
An aluminum alloy material for high-temperature high-speed forming, characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm exist as Mn and Zr-based precipitates at a distribution density of 300,000 particles / mm ² or more ,
(3) Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, Cu: 0.05 to 1.0 mass% containing the balance a Atsushi Ko high speed molding aluminum alloy material ing of Al and unavoidable impurities,
An aluminum alloy material for high-temperature high-speed forming, characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm exist as Mn and Zr-based precipitates at a distribution density of 300,000 particles / mm ² or more ,
(4) Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, Cu: 0.05 to 1.0 mass% Further, Cr: 0.05-0.5 mass%, V: 0.01-0.1 mass%, Sc: 0.01-0.4 mass%, Ti: 0.001-0.1 mass%, B: 0.0001-0.05 mass%, Be: 0.0001- containing one or more of 0.01 mass%, the balance being a high-temperature high-speed molding aluminum alloy material ing of Al and unavoidable impurities,
An aluminum alloy material for high-temperature high-speed forming, characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm exist as Mn and Zr-based precipitates at a distribution density of 300,000 particles / mm ² or more ,
( 5 ) It is characterized by being used for high-temperature high-speed molding in which cooling is performed to room temperature at a cooling rate of 20 ° C./min or more immediately after molding at a temperature of 200 to 550 ° C. and a strain rate of 10 ⁻² to 10 / sec ( 1) to the aluminum alloy material for high-temperature high-speed forming according to any one of ( 4 ),
( 6 ) Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, the balance being Al and An aluminum alloy ingot made of inevitable impurities is subjected to a homogenization treatment at 350 to 550 ° C. for 1 to 48 hours, and / or either hot working or cold working on the alloy ingot after the homogenization treatment. Characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm are present in a distribution density of 300,000 particles / mm ² or more as Mn and Zr-based precipitates in the aluminum alloy material by a process including at least a step of performing A method for producing an aluminum alloy material for high temperature and high speed forming,
( 7 ) Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, and Cr: 0.05 to 0.5 mass%, V: 0.01 to 0.1 mass%, Sc: 0.01 to 0.4 mass%, Ti: 0.001 to 0.1 mass%, B: 0.0001 to 0.05 mass%, Be: 0.0001 to 0.01 mass% A process of homogenizing an aluminum alloy ingot containing two or more types, the balance being Al and inevitable impurities, at 350 to 550 ° C. for 1 to 48 hours, and heating the alloy ingot after the homogenization process And at least including a step of performing either or both of cold working and cold working, 300,000 particles / mm ² of 10 to 1000 nm diameter intermetallic compound particles as Mn and Zr-based precipitates in the aluminum alloy material. A method for producing an aluminum alloy material for high-temperature high-speed forming, characterized by being present in the above distribution density,
( 8 ) Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, Cu: 0.05 to 1.0 mass% Aluminum alloy ingot containing Al and inevitable impurities, and a process of homogenizing at 350 to 550 ° C. for 1 to 48 hours, and hot working on the alloy ingot that has undergone the homogenization treatment Distribution of 300,000 particles / mm ² or more of intermetallic compound particles having a diameter of 10 to 1000 nm as Mn and Zr-based precipitates in the aluminum alloy material by a process including at least a process of performing either or both of cold working A method for producing an aluminum alloy material for high-temperature high-speed forming, characterized by being present in a density;
( 9 ) Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, Cu: 0.05 to 1.0 mass% Further, Cr: 0.05-0.5 mass%, V: 0.01-0.1 mass%, Sc: 0.01-0.4 mass%, Ti: 0.001-0.1 mass%, B: 0.0001-0.05 mass%, Be: 0.0001- A step of homogenizing at 350 to 550 ° C. for 1 to 48 hours on an aluminum alloy ingot containing one or more of 0.01 mass% and the balance being Al and inevitable impurities, and the homogenization By performing a process including at least a process of performing hot processing and / or cold processing on the alloy ingot that has undergone the treatment, an Mn and Zr-based precipitate between the metals having a diameter of 10 to 1000 nm in the aluminum alloy material A method of producing an aluminum alloy material for high-temperature, high-speed forming, characterized by having compound particles present at a distribution density of 300,000 particles / mm ² or more,
( 10 ) The high temperature and high speed forming aluminum alloy material is cooled to room temperature at a cooling rate of 20 ° C./min or more immediately after forming at a temperature of 200 to 550 ° C. and a strain rate of 10 ⁻² to 10 / sec. The method for producing an aluminum alloy material for high-temperature and high-speed forming according to any one of ( 6 ) to ( 9 ), wherein the method is used for forming,
( 11 ) The aluminum alloy material for high-temperature high-speed forming according to any one of (1) to ( 5 ) is formed at a high temperature and high speed at a temperature of 200 to 550 ° C. and a strain rate of 10 ⁻² to 10 / sec. The present invention provides a method for producing an aluminum alloy molded product characterized by immediately cooling to room temperature at a cooling rate of 20 ° C./min or more to make the metal structure a subcrystalline structure.

The high-temperature high-speed molding referred to in the present invention is a molding method performed at a temperature range of 250 to 550 ° C. and a strain rate of 10 ⁻² to 10 / s. Including a press molding method and a mold molding method.
Further, the subgrain structure referred to in the present invention is classified as a normal grain boundary with a grain boundary angle of 15 degrees or more, and a grain boundary with an angle difference of less than 15 degrees as a subgrain boundary. This refers to a structure in which the average value of the ratio of the sub-crystal grain boundaries in all the grain boundaries including the crystal grain boundaries and the sub-crystal grain boundaries is 5% or more.

  The present invention makes it possible to disperse transition element-based dispersed particles uniformly and in a high density in the matrix, allowing the subcrystalline structure to exist stably during and after the molding process, and excellent high-temperature and high-speed formability. And an aluminum alloy material for high-temperature high-speed forming having strength after forming. Further, by using the aluminum alloy material of the present invention, it becomes possible to mass-produce molded products having complicated shapes that are difficult to be formed by a conventional cold press.

Hereinafter, the present invention will be described in detail.
First, the reasons for limiting the alloy components are shown below.
In the present invention, the content of magnesium (Mg) is 2.0 to 8.0 mass%. Mg is an essential element that imparts high-temperature high-speed formability to aluminum (Al), and at the same time contributes to improving the strength of the molded product by solid solution hardening. If the amount of Mg is less than 2.0 mass%, sufficient high-temperature high-speed molding elongation cannot be obtained, and at the same time, the strength of the molded product is greatly reduced. On the other hand, when the Mg content is more than 8.0 mass%, the hot rolling property is significantly lowered, and it becomes difficult to produce a material for high-temperature high-speed forming by rolling. The content of Mg is preferably 2.4 to 7.6 mass%.

The content of manganese (Mn) is 0.05 to 1.0 mass%. Moreover, the content of zirconium (Zr) is 0.01 to 0.3 mass%.
In the present invention, Mn and Zr are essential elements. These are precipitated uniformly and densely as dispersed particles in the matrix by a homogenization process that is normally performed subsequent to casting, stabilizing the subgrain structure formed in the crystal grains during high-temperature high-speed molding, and during molding and It prevents the subcrystalline structure from disappearing due to recrystallization after the molding. This increases the high-temperature and high-speed molding elongation and at the same time contributes to improving the strength of the molded product.

  These dispersed particles need to be distributed without gaps in the matrix. If the area where the dispersed particles do not exist is relatively wide, the sub-crystal grains present in that area are not stabilized and grow as recrystallization nuclei. Regardless of the growth, the subgrain structure disappears by growing as coarse recrystallized grains.

  By containing an appropriate amount of both Mn and Zr elements, the dispersed particles can be distributed without gaps. The reason for this will be described below. In an aluminum alloy ingot produced industrially, Mn added in an appropriate amount tends to segregate during solidification, and the concentration tends to be low in the initially solidified region and high in the finally solidified region. For this reason, the distribution of the Mn-based dispersed particles after the homogenization treatment is not uniform, and there is a region where there are few Mn-based dispersed particles particularly in the initial solidification region where the amount of Mn is small. On the other hand, although Zr also segregates, contrary to Mn, the concentration tends to be high in the initial solidification region and low in the final solidification region. For this reason, during the homogenization treatment, the Zr-based dispersed particles are mainly precipitated in a region where there are few dispersed Mn particles. For this reason, by simultaneously adding Mn and Zr, Mn or Zr-based dispersed particles are dispersed in the matrix without any gaps, contributing to stabilization of the subcrystalline structure in the entire region of the structure. When only one of Mn and Zr is added, a region in which dispersed particles do not exist is generated, so that the subcrystalline structure cannot be stabilized over the entire region of the structure.

In order to effectively stabilize the subgrain structure by the dispersed particles, the size of the Mn-based and Zr-based dispersed particles is preferably 10 to 1000 nm, and the distribution density of the dispersed particles is 300,000 particles / mm ^2. The above is preferable. In the present invention, intermetallic compound particles having a diameter of 10 to 1000 nm as Mn and Zr-based precipitates are preferably present at a distribution density of 300,000 particles / mm ² or more, and at a distribution density of 450,000 particles / mm ² or more. More preferably. The distribution density and diameter of the intermetallic compound particles in the aluminum alloy material can be measured by analyzing an observation photograph obtained by observing a thin aluminum alloy sample with a transmission electron microscope. Further, it can be confirmed that the precipitates are Mn and Zr-based intermetallic compound particles by performing an elemental analysis of each precipitate with an elemental analyzer provided in a transmission electron microscope.

  When the Mn content is 0.05 mass% or less and the Zr content is 0.01 mass% or less, the effect of stabilizing the sub-crystal structure is poor. When the Mn content is 1.0 mass% or more and the Zr content is 0.3 mass% or more, a huge metal is cast. An intermetallic compound is generated and becomes a starting point of fracture during high-temperature high-speed molding, so that the high-temperature high-speed moldability is greatly reduced. The Mn content is preferably 0.2 to 0.8 mass%, and the Zr content is preferably 0.05 to 0.20 mass%.

In the present invention, the content of silicon (Si), which is an essential element, is 0.06 to 0.4 mass%, and the content of iron (Fe) is 0.06 to 0.4 mass%.
Fe / Si has the effect of improving high-temperature high-speed formability by refining the crystal grains of aluminum alloy material for high-temperature high-speed forming. Specifically, during annealing after cold working, which is a manufacturing process for aluminum alloy materials for high-temperature, high-speed forming, the crystallized material having a size of about 1 to 5 μm mainly composed of Fe / Si is regenerated as the nucleus. By the formation of crystals, the crystal grain size of the aluminum alloy material for high-temperature high-speed forming becomes fine, and the subsequent high-temperature high-speed formability is improved. If the amount of Fe / Si is less than 0.06 mass%, the above effects are poor, and if the amount of Fe / Si is more than 0.4 mass%, a huge intermetallic compound is generated during casting, which becomes the starting point of fracture during high-temperature high-speed forming. As a result, the high-temperature and high-speed formability is significantly reduced. The content of Si is preferably 0.10 to 0.35 mass%, and the content of Fe is preferably 0.10 to 0.35 mass%.

In the present invention, 0.05 to 0.5 mass% of chromium (Cr), 0.01 to 0.1 mass% of vanadium (V), and 0.01 to 0.4 mass% of scandium (Sc) can be optionally contained.
Cr / V / Sc, like Mn / Zr, precipitates as dispersed particles in the matrix by homogenization and contributes to the stabilization of the sub-grain structure formed during high-temperature high-speed forming. This has the effect of improving the strength of the molded product at the same time. When the Cr content is 0.05 mass% or less, the V content is 0.01 mass% or less, and the Sc content is 0.01 mass% or less, these effects are poor. On the other hand, if the Cr amount is 0.5 mass% or more, the V amount is 0.1 mass% or more, and the Sc amount is 0.4 mass% or more, a huge intermetallic compound is generated during casting, and the high-temperature high-speed formability is greatly reduced. . When each is contained, the Cr content is preferably 0.05 to 0.35 mass%, the V content is preferably 0.02 to 0.08 mass%, and the Sc content is preferably 0.05 to 0.25 mass%.

  In the present invention, 0.001 to 0.1 mass% of titanium (Ti) and 0.0001 to 0.05 mass% of boron (B) can be optionally contained. Ti / B refines the crystal grain of the ingot, and as a result, the crystal grain size of the material before molding is refined, thereby improving high-temperature and high-speed formability. When the Ti content is 0.001 mass% or less and the B content is 0.0001 mass% or less, the above-mentioned effects are poor, and when the Ti content is 0.1 mass% or more and the B content is 0.05 mass% or more, a large crystal is formed, and high temperature and high speed are formed. Formability will be significantly reduced. When each is contained, the content of Ti is preferably 0.005 to 0.05 mass%, and the content of B is preferably 0.0005 to 0.005 mass%.

  In the present invention, 0.0001 to 0.01 mass% beryllium (Be) can be optionally contained. Be suppresses the oxidation of Mg on the surface of an aluminum alloy material for high-temperature high-speed forming during high-temperature forming and stabilizes the surface, thereby improving the coating and anodizing treatment properties that are subsequently performed after forming. If the amount of Be is 0.0001 mass% or less, the above effect is not exhibited. If the amount of Be is 0.01 mass% or more, the above effect is saturated, which is economically problematic. When contained, the content of Be is preferably 0.0005 to 0.005 mass%.

  In the present invention, it is possible to arbitrarily contain 0.05 to 1.0 mass% of copper (Cu). Cu keeps the molded product at room temperature for 1 day or more after completion of high-temperature and high-speed molding, or keeps it at a temperature of 100 ° C. or more for 1 hour or more to precipitate in the matrix and contribute to improvement of the strength of the molded product. In the case of improving the strength by such Cu precipitation, it is necessary to cool the molded product to room temperature as soon as possible after completion of the high-temperature high-speed molding. The cooling rate from the molding temperature to room temperature is preferably 20 ° C./min or more. If the Cu amount is 0.05 mass% or less, the above effect is not exhibited. On the other hand, if the amount of Cu is 1.0 mass% or more, the corrosion resistance of the molded product is significantly reduced. When contained, the content of Cu is preferably 0.1 to 0.8 mass%.

  The aluminum alloy material for high-temperature and high-speed forming of the present invention only needs to satisfy the above conditions as the chemical component composition, but in order to ensure good high-temperature high-speed formability and high strength of the molded product, It is preferable that the structure after molding is made of a subcrystalline structure by molding under the molding conditions described.

  In the present invention, the high-temperature high-speed molding temperature is in the range of 200 to 550 ° C. When the molding temperature is less than 200 ° C., sufficient high-temperature and high-speed molding elongation cannot be obtained, and a molded product having a complicated shape that is difficult to mold by a cold press cannot be obtained. On the other hand, when the molding temperature is 550 ° C. or higher, the Mn / Zr-based dispersed particles precipitated uniformly and densely in the matrix in order to stabilize the sub-grain structure formed during molding are formed in the matrix during molding. By re-dissolving and disappearing, recrystallization occurs during molding or after completion of molding, and the subcrystalline structure disappears. The high temperature and high speed molding temperature is preferably 300 to 500 ° C.

The average strain rate during high-temperature high-speed molding of the present invention is 10 ^-2 to 10 / s. Molding at a strain rate of 10 ⁻² / s or less is technically possible, but it is not economical because the productivity is remarkably inferior. On the other hand, when the strain rate is 10 / s or more, the deformation rate is too high and a subcrystalline structure is not formed, so that the high-temperature high-speed moldability is remarkably deteriorated and it becomes impossible to mold into a complicated shape. The strain rate is preferably 10 ⁻² to 1 / s.
Furthermore, it is preferable that the cooling rate to room temperature after high-temperature high-speed molding is 20 ° C./min or more. When the cooling rate is 20 ° C./min or less, recrystallization occurs during the cooling process, so that the sub-crystal grains disappear and the strength of the molded product is greatly reduced. The cooling rate to room temperature after high-temperature high-speed molding is more preferably 40 ° C./min or more.

  Next, during the cooling process after high-temperature high-speed molding and during the cooling process after high-temperature high-speed molding, recrystallization does not occur, and the structure of the molded product is composed of the subcrystalline structure formed during high-temperature high-speed molding, thereby achieving good high-temperature high-speed molding The reason why the high strength of the molded product is ensured while the properties are obtained will be described below.

  First, the reason why the high-temperature high-speed formability is improved by the sub-crystal grain structure is that the rotation of the individual sub-crystal grains in the fine sub-crystal structure formed in the crystal grains during the high-temperature high-speed molding is the main factor during the high-temperature high-speed molding. This is because the deformation mechanism overlaps with intragranular deformation and grain boundary sliding. For this reason, when recrystallization occurs locally during high-temperature high-speed forming and the subcrystalline structure disappears, the high-temperature high-speed elongation at that site rapidly decreases and becomes the starting point of fracture, greatly increasing the high-temperature high-speed forming elongation. descend.

  On the other hand, the improvement in the strength of the molded product due to the subcrystalline structure results from the fact that the intragranular matrix is strengthened by the crystal grains being composed of subcrystalline grains. In this case, the yield strength of the molded product tends to increase as the grain size of the sub-crystal grains decreases. Since the grain size of the sub-crystal grains becomes smaller as the strain rate at the time of molding becomes higher, it is better to mold at a higher strain rate in order to increase the strength of the molded product.

  Below, the manufacturing method of the aluminum alloy material in this invention is demonstrated. The alloy material of the present invention can basically be manufactured by a method usually employed in the aluminum alloy manufacturing industry. That is, an aluminum alloy melt adjusted to be within the component specification range of the present invention is cast by appropriately selecting a normal melting casting method. Here, the normal melt casting method includes, for example, a semi-continuous casting method (DC casting method), a thin plate continuous casting method (roll casting method, etc.) and the like.

  Next, the aluminum alloy ingot is subjected to homogenization treatment. The homogenization treatment is a step performed to deposit dispersed particles containing a transition element such as Mn / Zr as a component in the matrix uniformly and with high density. It is preferably carried out at 350 to 550 ° C. for 1 to 48 hours, more preferably at 400 to 530 ° C. for 8 to 24 hours. An aluminum alloy material for high-temperature and high-speed forming can be manufactured by carrying out hot working and / or cold working after chamfering as appropriate before or after this homogenization treatment step. . At this time, intermediate annealing may be appropriately performed as necessary, and final annealing may be performed. Here, the hot working / cold working may be any of rolling, extruding, drawing, and forging that are usually performed depending on the final form of the aluminum alloy material for high-temperature high-speed forming to be manufactured. . The shape of the aluminum alloy material for high-temperature high-speed molding produced includes a plate, a cylinder, a rectangular tube, and other hollow tubes having a complicated cross-sectional shape.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Example 1
Aluminum alloys having chemical components shown in Table 1 were melted at 700 ° C. and cast by the DC casting method. After chamfering the obtained ingot, homogenization treatment was performed at 510 ° C. for 8 hours, hot rolling was started at 490 ° C., the plate thickness was 5 mm at 280 ° C., and the hot rolling was finished. Thereafter, after intermediate annealing at 400 ° C. for 3 hours, cold rolling was performed to a plate thickness of 1 mm. Finally, this cold rolled sheet was annealed at 520 ° C. for 20 seconds to form a recrystallized structure, and then subjected to the following test.

First, a thin film sample having a thickness of about 0.3 μm was prepared from these test materials, and the distribution density of intermetallic compounds was examined with a transmission electron microscope. The results are summarized in Table 2. When the distribution density of the intermetallic compound having a diameter of 10 to 1000 nm is 300,000 pieces / mm ² or more, it is indicated by ◯, and when it is less than this, it is indicated by ×. In addition, about alloy No. 10 of the comparative example, since the said thin film sample was not able to be created, it did not measure.

Next, a tensile test piece (width 4 mm x parallel part length 15 mm) was prepared from the above-mentioned test material, and a high-temperature tensile test was conducted at 500 ° C under a strain rate of 10 ^-1 / s. The results are summarized in Table 3. In the present invention, when high temperature high speed elongation of 150% or more was obtained, it was judged that the film had good high temperature high speed moldability.
Next, a 300 mm square sample was cut out from these cold-rolled plates, and high-temperature high-speed blow molding was performed using a small blow molding machine that performs molding using the pressure of an inert gas. A square tube mold with a side of 250 mm and a height of 60 mm is used as the mold, and after setting the sample on the molding machine and heating to a molding temperature of 500 ° C, the average strain rate is about 10 ^-1 / s The pressurization speed of the inert gas was controlled so that a high temperature high speed molding with a height of 60 mm was performed. Immediately after molding, the sample was removed from the molding machine and cooled to room temperature at a cooling rate of 40 ° C./min or more. A tensile test was conducted by collecting a JIS No. 5 tensile test piece in the rolling direction from the center of the upper surface of the rectangular tube molded product. The resulting 0.2% proof stress values are shown in Table 3.

  Furthermore, in order to investigate whether the structure of these molded products is composed of subgrain structures, the rectangular tube molded products separately formed by high-temperature high-speed blow molding under the same temperature and strain rate conditions shown in the schematic diagram of FIG. Samples of 10 × 10 mm were collected from the upper surface central portion 2, the upper surface corner portion 3, and the rising portion 4, respectively, and subjected to grain boundary analysis by the method described below. First, these samples were mechanically polished to the center in the plate thickness direction, and then subjected to electrolytic polishing as a mirror surface by finish polishing to expose the plate thickness center of the molded product. After that, this sample was set in a scanning electron microscope equipped with an electron backscatter diffraction image analyzer capable of crystal grain boundary analysis, and the grain boundaries in the 200 × 200 μm region of the exposed portion were analyzed. . Based on the analyzed data, grain boundaries with a grain boundary angle of 15 degrees or more are classified as normal grain boundaries, and grain boundaries with an angle difference of less than 15 degrees are classified as subgrain boundaries. The ratio of the sub-crystal grain boundary in all the grain boundaries including the sub-crystal grain boundary was calculated, and the ratio of the sub-crystal grain boundary for each part of the molded product was summarized in Table 3. In this example, three locations where samples were collected based on a large number of test data accumulated on the relationship between the ratio of sub-grain boundaries formed during high-temperature high-speed forming and the relationship between high-temperature high-speed formability and strength after forming. When the average value of the sub-crystal grain boundary ratio is 5% or more, it is judged that the molded product is composed of the sub-crystal grain structure. Those which are not tissues are indicated by ×. In addition, if the high-temperature high-speed elongation is insufficient and it is impossible to mold to 60 mm, which is the height of the used square tube mold, and it breaks in the middle, the molding is immediately interrupted and the cooling rate is the same. After cooling, a sample (10 × 10 mm) was taken from the vicinity of the fracture and subjected to the same grain boundary analysis, and the ratio of the obtained subgrain boundaries was shown in Table 3 for reference.

When the alloy materials 1 to 8 within the range of the present invention are deformed at a temperature (500 ° C.) and a strain rate (10 ⁻¹ / s) within the range of the present invention, in each case, high temperature and high speed elongation of 150% or more is exhibited. It is clear that it has good high-temperature high-speed moldability. Similarly, in the high-temperature high-speed blow molding using a rectangular tube mold under the temperature and strain rate conditions within the range of the present invention, any alloy material can be molded to a height of 60 mm. Furthermore, the structure after cooling to room temperature under the cooling rate condition (40 ° C./min) within the scope of the present invention was a subgrain structure in any alloy material.

On the other hand, the alloy material 9 as a comparative example has an Mg amount that is less than the specified range of the present invention, so sufficient high-temperature high-speed elongation cannot be obtained, and the high-temperature high-speed blow molding breaks until reaching a height of 60 mm. It was.
In addition, the alloy material 10 as a comparative example has an Mg amount that is not less than the specified range of the present invention, the hot rolling property is extremely poor, and cracks occurred during rolling, and thus a test material having a thickness of 1 mm could not be produced. .
In addition, since the alloy material 11 and the alloy material 12 of the comparative example each have one of the amounts of Mn · Zr to be co-added in a specified amount is smaller than the range of the present invention, the distribution density of Mn · Zr-based dispersed particles is 30,000 / Since it was less than mm ² and the distribution was non-uniform, recrystallization occurred in a region where the distribution density was low, and as a result, the subgrain structure disappeared. As a result, sufficient high-temperature and high-speed elongation could not be obtained. This result supports the effectiveness of co-addition of Mn and Zr. Further, in the crystal structure after the high-temperature high-speed blow molding, the subgrain structure disappeared on the entire surface. In this case, the 0.2% yield strength is lower by about 15 MPa than the 0.2% yield strength of the alloy material 1 of the present invention in which the Mg amount is almost the same and the molded product is made of a subcrystalline structure. This confirms that the strength of the alloy material of the present invention is improved by maintaining the subgrain structure after forming.

Further, the alloy materials 13, 14, 15, and 17 of the comparative examples each have a larger amount of Mn, Zr, Si · Fe, Cr · V · Sc than the scope of the present invention, so that a coarse intermetallic compound is produced during casting. Thus, since this becomes the starting point of fracture at high temperature and high speed deformation, the high temperature and high speed elongation is remarkably low, and good high temperature and high speed moldability cannot be obtained. Therefore, it is impossible to mold 60 mm in high temperature blow molding.
The alloy material 16 of the comparative example had insufficient high-temperature high-speed forming elongation because the amount of Fe · Si was less than the range of the present invention.

(Example 2)
Tensile specimens (rolling tension width 4 mm, parallel part length 15 mm) were prepared from the specimen material of the present invention alloy material 1 shown in Table 1 having a thickness of 1 mm shown in Table 1, and the temperature and strain shown in Table 4 were obtained. A high-speed high-speed deformation of 150% was given under the speed condition. Immediately after that, it was cooled to room temperature at the cooling rate shown in Table 4. A sample (10 mm × 4 mm) for grain boundary analysis was taken from the central region of the parallel part of the tensile test piece after this high-temperature and high-speed deformation, and the grain boundary at the center plane in the plate thickness direction was obtained by the method described in Example 1. Analysis was performed to calculate the ratio of sub-grain boundaries to the total grain boundaries, and the results are summarized in Table 4. As in the case of Example 1, when the ratio of the sub-crystal grain boundary was 5% or more, it was judged that the structure was composed of sub-crystal grains. If the elongation breaks at less than 150% during high-temperature and high-speed deformation, the test is immediately stopped, the sample is removed, cooled to room temperature at the cooling rate shown in Table 4, and used for grain boundary analysis from the vicinity of the fracture. The sample was collected and the grain boundary analysis was performed by the same method.

  In conditions 1 to 9 when the alloy material 1 within the range of the present invention is formed at a temperature and strain rate within the range of the present invention, 150% high-temperature and high-speed elongation is obtained. It is clear that high speed moldability can be obtained. Further, immediately after the deformation, the grain boundary analysis was performed after cooling to room temperature at a cooling rate within the range of the present invention. As a result, in all cases, this sample was composed of a subgrain boundary structure.

  On the other hand, conditions 10 to 13 which are comparative examples in which the alloy material 1 that is componentally within the scope of the present invention is formed at a high temperature and high speed under conditions outside the scope of the present invention will be described below. Under condition 10, since the deformation temperature is lower than the range of the present invention, the high-temperature high-speed elongation is low and good high-temperature high-speed moldability cannot be obtained. On the other hand, in condition 11, the deformation temperature is higher than the range of the present invention, and the Mn / Zr-based dispersed particles contributing to the stabilization of the subgrain structure re-dissolve, and recrystallization occurs during deformation, resulting in high temperature and high speed elongation. Decreased significantly. Furthermore, under condition 12, the strain rate is too high, so a subcrystalline structure is not formed, and the high-temperature high-speed forming elongation is low. Under condition 13, there was 150% high-temperature high-speed elongation, but the cooling rate after high-temperature high-speed deformation was lower than the scope of the present invention, so recrystallization occurred during cooling, and the subcrystalline structure formed during high-temperature high-speed molding Disappeared, and the strength improvement due to the subcrystalline structure was not obtained.

FIG. 3 is a schematic diagram showing a sample collection site for crystal grain boundary analysis from a rectangular tube molded product in Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Square tube molded product 2 Upper surface center part 3 Upper surface corner part 4 Rising part

Claims (11)

Mg: 2.0-8.0mass%, Mn: 0.05-1.0mass%, Zr: 0.01-0.3mass%, Si: 0.06-0.4mass%, Fe: 0.06-0.4mass%, the balance from Al and inevitable impurities a high temperature high-speed molding aluminum alloy material Do that,
An aluminum alloy material for high-temperature high-speed forming, characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm are present as Mn and Zr-based precipitates at a distribution density of 300,000 particles / mm ² or more . Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, further Cr: 0.05 to 0.5 mass%, V: 0.01 to 0.1 mass%, Sc: 0.01 to 0.4 mass%, Ti: 0.001 to 0.1 mass%, B: 0.0001 to 0.05 mass%, Be: 0.0001 to 0.01 mass% containing the balance a Atsushi Ko high speed molding aluminum alloy material ing of Al and unavoidable impurities,
An aluminum alloy material for high-temperature high-speed forming, characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm are present as Mn and Zr-based precipitates at a distribution density of 300,000 particles / mm ² or more . Mg: 2.0-8.0mass%, Mn: 0.05-1.0mass%, Zr: 0.01-0.3mass%, Si: 0.06-0.4mass%, Fe: 0.06-0.4mass%, Cu: 0.05-1.0mass% the balance an aluminum alloy material for a Atsushi Ko high speed molding ing of Al and unavoidable impurities,
An aluminum alloy material for high-temperature high-speed forming, characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm are present as Mn and Zr-based precipitates at a distribution density of 300,000 particles / mm ² or more . Mg: 2.0-8.0mass%, Mn: 0.05-1.0mass%, Zr: 0.01-0.3mass%, Si: 0.06-0.4mass%, Fe: 0.06-0.4mass%, Cu: 0.05-1.0mass% Furthermore, Cr: 0.05-0.5 mass%, V: 0.01-0.1 mass%, Sc: 0.01-0.4 mass%, Ti: 0.001-0.1 mass%, B: 0.0001-0.05 mass%, Be: 0.0001-0.01 mass% one or comprise two or more, the balance being a high-temperature high-speed molding aluminum alloy material ing of Al and unavoidable impurities out of,
An aluminum alloy material for high-temperature high-speed forming, characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm are present as Mn and Zr-based precipitates at a distribution density of 300,000 particles / mm ² or more . It is used for high-temperature high-speed molding in which cooling is performed to room temperature at a cooling rate of 20 ° C / min or more immediately after molding at a temperature of 200 to 550 ° C and a strain rate of 10 ^-2 to 10 / sec. 5. The aluminum alloy material for high-temperature high-speed forming according to any one of 4 above. Mg: 2.0-8.0mass%, Mn: 0.05-1.0mass%, Zr: 0.01-0.3mass%, Si: 0.06-0.4mass%, Fe: 0.06-0.4mass%, the balance from Al and inevitable impurities A step of homogenizing the aluminum alloy ingot to be formed at 350 to 550 ° C. for 1 to 48 hours, and a step of performing hot working and / or cold working on the alloy ingot subjected to the homogenizing treatment. At a high temperature and high speed characterized in that intermetallic compound particles having a diameter of 10 to 1000 nm are present as a Mn and Zr-based precipitate in the aluminum alloy material at a distribution density of 300,000 particles / mm ² or more in the aluminum alloy material. Manufacturing method of aluminum alloy material for forming. Mg: 2.0 to 8.0 mass%, Mn: 0.05 to 1.0 mass%, Zr: 0.01 to 0.3 mass%, Si: 0.06 to 0.4 mass%, Fe: 0.06 to 0.4 mass%, further Cr: 0.05 to 0.5 mass%, V: 0.01-0.1mass%, Sc: 0.01-0.4mass%, Ti: 0.001-0.1mass%, B: 0.0001-0.05mass%, Be: 0.0001-0.01mass% Aluminum alloy ingot containing Al and inevitable impurities, and a process of homogenizing at 350 to 550 ° C. for 1 to 48 hours, and hot working on the alloy ingot that has undergone the homogenization treatment Distribution of 300,000 particles / mm ² or more of intermetallic compound particles having a diameter of 10 to 1000 nm as Mn and Zr-based precipitates in the aluminum alloy material by a process including at least a process of performing either or both of cold working A method for producing an aluminum alloy material for high-temperature high-speed forming, characterized by being present in a density. Mg: 2.0-8.0mass%, Mn: 0.05-1.0mass%, Zr: 0.01-0.3mass%, Si: 0.06-0.4mass%, Fe: 0.06-0.4mass%, Cu: 0.05-1.0mass% , A process of homogenizing the aluminum alloy ingot consisting of Al and inevitable impurities at 350 to 550 ° C. for 1 to 48 hours, and hot working / cold working to the alloy ingot after the homogenizing treatment In the aluminum alloy material, there exist at least 300,000 particles / mm ² of intermetallic compound particles having a diameter of 10 to 1000 nm as precipitates of Mn and Zr in the aluminum alloy material. A method for producing an aluminum alloy material for high-temperature high-speed forming, characterized in that: Mg: 2.0-8.0mass%, Mn: 0.05-1.0mass%, Zr: 0.01-0.3mass%, Si: 0.06-0.4mass%, Fe: 0.06-0.4mass%, Cu: 0.05-1.0mass% Furthermore, Cr: 0.05-0.5 mass%, V: 0.01-0.1 mass%, Sc: 0.01-0.4 mass%, Ti: 0.001-0.1 mass%, B: 0.0001-0.05 mass%, Be: 0.0001-0.01 mass% The aluminum alloy ingot containing 1 type or 2 types among them and the remainder consisting of Al and inevitable impurities is subjected to a homogenization process at 350 to 550 ° C. for 1 to 48 hours and the homogenization process. By performing a process including at least one of hot working and / or cold working on the alloy ingot, intermetallic compound particles having a diameter of 10 to 1000 nm as Mn and Zr-based precipitates in the aluminum alloy material. A method for producing an aluminum alloy material for high-temperature, high-speed forming, characterized by having a distribution density of 300,000 pieces / mm ² or more. The aluminum alloy material for high-temperature high-speed forming is used for high-temperature high-speed forming that cools to room temperature at a cooling rate of 20 ° C./min or more immediately after forming at a temperature of 200 to 550 ° C. and a strain rate of 10 ⁻² to 10 / sec. The method for producing an aluminum alloy material for high-temperature and high-speed forming according to any one of claims 6 to 9 . The aluminum alloy material for high temperature and high speed forming according to any one of claims 1 to 5 is formed at a high temperature and high speed at a temperature of 200 to 550 ° C and a strain rate of 10 ^-2 to 10 / sec, and immediately 20 ° C / min. A method for producing an aluminum alloy molded article, wherein the metal structure is changed to a subgrain structure by cooling to room temperature at the above cooling rate.

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